Patent GB-793774-A (GB)
Title: Improvements relating to the manufacture of footwear
Inventor: HAWKINS WALLACE GERALD
IPC: A43D25/053
Filed: 1954-01-29
Abstract: 793,774. Lasting machines. CLARK, Ltd.. C. & J. April 29, 1955 [Jan. 29, 1954], No. 2733/54. Class 17(1) An attachment for a lasting machine wherein the upper margin is pulled over on insole 37 of Figs. 1, 2 by a pair of oppositely rotating and oppositely tapering rolls 7, 11, and attached by cement, comprises a nozzle 35 for directing a jet of hot air on to pre-cemented margins of an insole 37 and upper 36 on a last to activate the cement prior to bonding the margins together, a valve body 4 mounted on a machine part supporting one of the rolls, a plunger 5 slidable in the valve body and when moved in one direction releasing to the nozzle air supplied under pressure to the valve body, a stop 8 mounted on another machine part supporting the other roll and normally restraining the plunger against air releasing movement, and an appliance 30 for heating air delivered to the nozzle, the arrangement being such that air is delivered to the nozzle on a prearranged relative movement of the roll-supporting parts. In one construction, hot air passes to the nozzle from a hot air generator which may comprise a drilled metal block heated by cartridge elements, or a metal tube coil heated by gas, or an electric element, air being blown through the block or tube or over the element, and air to the generator A is controlled by a restrictor K as shown in Fig. 3 of Provisional Specification, or by valve mechanism, shown in Fig. 3 of Complete Specification. The actuating valve B is attached to the sliding head and is opened by the mechanism D, comprising a preloaded spring actuated plunger, when the head moves. The mechanism is adjusted by stop screw J which determines the minimum clearance between the feed rolls. and screw H and locknut G which adjust the clearance between parts D and B. The adjustable restrictor K controls the amount of air entering the generator, and bleed valve C ensures that a small quantity of air constantly passes through the system to maintain the pipes near working temperature a thermocouple - controlled temperature indicator, and/or a thermostat control may be attached to the nozzle. In the construction shown in Fig. 2, parts B, C, D, G, and K are replaced by the valve shown in Fig. 3. When the rolls are closed the adjustable stop 8, on the part 10 supporting roll 11, prevents plunger 5 from moving so that valve 12 is held closed and air cannot pass via 16, 14, 3, 2, 1 to the heat generator 30, but when the rolls are spaced for feeding stop 8 is moved from plunger 5 which is moved by the air which passes to the generator. By-pass valve 19, normally closed by adjustable spring 20, is opened when plunger 17 is moved via adjustable screw 23, lever 24, interchangeable follower plates 26. the contours of which control the movement of the plunger, pin 28, and bar 29 which is displaced by the pedal which also controls the opening of rolls 7, 11, lost motion ensuring that hot air is supplied before the rolls rotate. Movement of the plunger may also be adjusted by means of elongated holes 27 in lever 24 and/or plates 26. On machines having automatic movement of rolls 7, 11, this movement is shared by stop 8 and imparted to plunger 5 permitting sufficient flow of air without use of valve 19. Specification 617,695 is referred to.